Ntp is a Network Time Protocol client. It connects your machine to a clock on the 'net somewhere and fetches the time from this clock, then sets the local clock (the one built-in to your computer). Since most clocks found on the internet are Atomic clocks they are precise. To get started, you'll want to pick a server. For more technical info on the Network Time Protocol please read RFC1305. RFCs can be found on many decent ftp servers, although a Google search is probably your best bet. .